Sensor device, particularly for controlling lighting devices of a motor vehicle

ABSTRACT

A sensor device is proposed, particularly for controlling lighting devices of a motor vehicle, having at least one receiver for receiving radiation from at least one receiver region, and a control device which is capable of controlling peripheral devices; a diffractive element, able to be attached to a window and formed preferably as a hologram, is provided which is arranged in the receiver region of the receiver.

FIELD OF THE INVENTION

The present invention relates to a sensor device, particularly forcontrolling lighting devices of a motor vehicle.

BACKGROUND INFORMATION

Numerous sensor devices are already known which are used for controllinglighting devices of motor vehicles. Such a sensor device is described,for example, in the German Published Patent Application No. 199 33 642.It has a bulky light-guiding member made of transparent plastic that issecured on the window of a motor vehicle via a coupling medium. Thislight-guiding member images the radiation of light from varioussolid-angle regions onto receivers, which, for their part, control thelighting devices via a suitable control device. Since the lightingconditions in the forward direction of the vehicle are particularlyrelevant for controlling the lighting devices, the light-guiding membermust be arranged on the windshield of the motor vehicle, which restrictsthe visual range of the driver because of the expansion of the sensordevice.

SUMMARY OF THE INVENTION

The sensor device of the present invention has the advantage that, dueto a diffractive element, which preferably takes the form of a hologram,a very small and compact sensor device is produced which does notrestrict the visual range of the driver, and nevertheless, optimallycontrols the peripheral devices. To that end, the diffractive element isarranged in the receiver region of a receiver, so that the receiverreceives radiation from the surroundings, e.g. sunlight or artificiallight from specific relevant space areas, and relays to a controldevice.

If the diffractive element is formed in the receiver region of thereceivers in such a way that it images radiation from various spatialreception regions onto a single receiver, then an optimal response ofthe sensor device results, since reaction is possible in adifferentiated fashion to the various lighting conditions in differentdirections around the motor vehicle.

It is particularly advantageous if a plurality of receptions areprovided which detect radiation from various spatial reception regions,and a single diffractive element is provided for all reception regions.The individual brightness signals from the various spatial receptionregions are thereby each available individually, making it possible tooptimally control the individual lighting devices or other peripheraldevices of the motor vehicle. Because a single diffractive element isprovided for all reception regions, particularly for a global anddirectional sensor system, the costs of a sensor device according to thepresent invention are reduced to a minimum.

In this context, it is particularly advantageous if the receiver has alight-sensitive receiver element and a light guide. The receiverelement, which typically has a semiconductor structure, may be arrangedoutside of the window of the motor vehicle in such a way that only thediffractive element and the light guide, which do not impair the outwardvisibility from the vehicle, are positioned in the visual range of thedriver.

If the diffractive element has a first region which, in the mountedposition, images radiation from the forward direction of the motorvehicle onto the receiver, and has a second region which, in the mountedposition, images radiation from an angular range, that correspondsapproximately to the direction of surface normal of the window, onto thereceiver, then, on one hand, it is possible to detect the totalbrightness in the vicinity of the vehicle, and nevertheless, to react todark stretches lying in front of the vehicle such as, for example,tunnel or bridge passages.

It is particularly advantageous if the diffractive element iscontrollable, so that the reception region is adjustable as a functionof control signals. In this way, for example, measurements may becarried out in alternation in the forward direction and in the directionof surface normal of the window, and thus information may be obtainedfrom several different reception regions with the aid of a singlereceiver and a single diffractive element. This yields a more precisecontrol of the peripheral devices, while the costs for the sensor deviceare only increased a little. In this context, it is particularlyadvantageous if the diffractive element is controllable periodically.

Furthermore, it must be regarded as advantageous if the diffractiveelement is formed in one piece with a further diffractive element of arain sensor. A compact assembly for controlling a windshield wiperdevice, as well as for controlling lighting devices is thereby madeavailable. Naturally, the aforesaid features may also be transferredcorrespondingly to a rain sensor device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sensor device according to the present invention in aschematic cross-sectional representation.

FIG. 2 shows a variation of a sensor device according to the inventionfrom FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows a schematic cross-sectional representation of a sensordevice according to the present invention. Sensor device 10 is madeessentially of a diffractive element 12 formed as a hologram film. Thishologram film 12 is pasted or fastened in another manner on a window 14,e.g., the windshield of a motor vehicle; naturally, diffractive element12 may also be disposed in window 14.

Light-sensitive reception elements 13 are positioned as receivers 16, 18on the side of diffractive element 12 facing away from window 14.Diffractive element 12 is divided into a first region 20 and a secondregion 22, and is formed in such a way that receives light from theforward direction of the motor vehicle, indicated by arrow 24, andimages on first receiver 16. An acceptance cone a having a width ofapproximately 20° is thereby formed, which detects radiation from theforward direction. Therefore, here less light radiation is detected infront of a tunnel entrance than on the open road. Second region 22 ofdiffractive element 12 is formed in such a way that radiation fromdirection of surface normal 26, which is perpendicular to window 14, isimaged onto the second receiver. In this context, the reception regionis selected so that the ambient brightness above the vehicle isdetected. To that end, the cone has a dissymmetry, so that radiationfrom upward, up to Ω=45° with respect to the direction of surfacenormal, is detected, and radiation is also detected in the lowerdirection ρ=10° with respect to the direction of surface normal. Thus, atotal acceptance cone Ω+ρ of approximately 55° results. Both receivers16, 18 are connected to a control device 28 in which, for example,switching thresholds are stored; when there is a drop below theseswitching thresholds or they are exceeded, lighting devices 30 areswitched on or switched off.

FIG. 2 shows a variation of the sensor device according to the presentinvention from FIG. 1. The hologram film is again pasted as diffractiveelement 12 on window 14. In front of their light-sensitive receiverelements 13, receivers 16, 18 have first light guides 32 and secondlight guides 34, connected correspondingly to first region 20 and secondregion 22, which guide the light to receiver elements 13 that aredisposed, for example, in the roof of the motor vehicle, outside ofwindow 14, and therefore are not visible to the driver. These receivers16, 18 are in turn connected to control device 28 which controlslighting devices 30.

Naturally, any other peripheral devices 30 may be controlled by sensordevice 10 according to the present invention. Presenting themselves forthis purpose are, for example, sun roofs, sun blinds, convertible tops,heating, ventilation, air conditioner system, recirculation flap andwindshield wiper/washer devices, but also door locks, i.e., the centrallocking system. In addition, it is conceivable to limit the vehiclespeed when a tunnel is detected, or when lighting conditions on thewhole become poorer. Moreover, sensor device 10 may also be used toprogram other devices of the motor vehicle. This may be accomplished,for example, by temporarily positioning a selectively controllable lightsource on the vehicle in the area of sensor device 10, the light sourcebeing controlled via specific light signals that correspond to a coding.Sensor device 10 may thereby also be used as an input port for a motorvehicle, which is advantageous especially when the motor vehicle islocked. Thus, it may be useful to have the motor vehicle opened by thecentral locking system when specific signals are relayed by firstreceiver 16 and/or second receiver 18.

1. A sensor device, comprising: at least one receiver for receivingradiation from at least one receiver region and detecting a peripheralbrightness of surroundings of a vehicle; a control device capable ofcontrolling a lighting device of the vehicle as a function of signalsfrom the receiver; and a diffractive element capable of being attachedto a window of the vehicle and positioned in the at least one receiverregion of the at least one receiver.
 2. The sensor device as recited inclaim 1, wherein: the diffractive element is formed as a hologram. 3.The sensor device as recited in claim 1, wherein: the diffractiveelement is formed in the at least one receiver region in such a way thatthe diffractive element images radiation from various delimited, spatialreception regions onto a single one of the at least one receiver.
 4. Thesensor device as recited in claim 1, wherein: the at least one receiverincludes a plurality of receivers for detecting radiation from variousspatial reception regions, and the diffractive element is provided forall the various spatial reception regions.
 5. The sensor device asrecited in claim 1, wherein: the at least one receiver includes alight-sensitive receiver element and a light guide.
 6. The sensor deviceas recited in claim 1, wherein: the diffractive element includes atleast one first region that, in a mounted position, images radiationfrom a forward direction of a motor vehicle onto the at least onereceiver, the diffractive element includes a second region that, in themounted position, images radiation from an angular range correspondingapproximately to a direction of surface normal of the window, onto theat least one receiver.
 7. The sensor device as recited in claim 1,wherein: the diffractive element is controllable, so that the at leastone receiving region is adjustable as a function of a control signal. 8.The sensor device as recited in claim 7, wherein: the diffractiveelement is controllable periodically.
 9. The sensor device as recited inclaim 1, wherein: the diffractive element is formed in one piece with afurther diffractive element of a rain sensor.